1. Field of the Invention
The present invention relates to a method of fabricating a light emitting diode (LED), and more specifically to a simple method of simultaneously fabricating multiple LED devices in a single procedure.
2. Description of Related Art
With reference to FIG. 9, a conventional lead package for an LED device before applying the encapsulant includes a first lead (71), a second lead (72) and a die (73). The second lead (72) has a top face (not numbered), and a reflecting taper tube (720) is formed on the top face. The die (73) mounted in the reflecting taper tube (720) is connected between the first and second leads (71, 72) by a wire bonding process. After the wire bonding process, the die (73), and the first and second leads (71, 72) are encapsulated with encapsulant to form a completed LED device product.
The forgoing LED device has many drawbacks.
(1) The LED device only has one color. If the LED device has two colors, the LED device needs another lead.
(2) The fabricating process of the LED device is complex. That is, the fabricating process comprises at least a fabricating lead step, a mounting the die step, a wire bonding step and an encapsulating step. The encapsulating step requires a mold so the production rate for these LED devices is not very large.
(3) Combining the LED device with a PCB has very tedious steps, such as inserting the leads into correct conducting holes on the PCB, soldering the lead and the conducting hole and cutting off any excess portion of the lead.
(4) The LED device is hard to assemble into a display module. The LED device uses the leads to hold the die so assembling multiple LED devices into a display module is not easy.
Based on the forgoing description, the production rate of the lead package of the LED device is low, and attaching the led package to a PCB is not easy. Therefore, a surface mounted technology (SMT) LED device was developed. With reference to FIG. 10, the conventional SMT LED device has a substrate (86), two electrodes (81,82) and a die (83). The substrate (80) has two opposite ends (not numbered) and a top face (not numbered). The two electrodes (81, 82) are formed respectively on the opposite ends of the substrate (80). The die (83) is deposited on the substrate (80) and is connected to the two electrodes (81, 82) by a wire bonding process. After the wire bonding process, encapsulant (84) is applied to the top face of the substrate (80) with the die (83) to complete the SMT LED device. The SMT LED devices can be easily assembled into an LED display module by mounting more dies (83) on the substrate (80). In addition, the SMT LED device can be soldered quickly on the PCB to improve the production rate.
The steps to fabricate the SMT LED device are simpler than those required to fabricate the conventional LED device. However, some steps can be further improved to simply the steps in the SMT LED fabricating process.
The present invention provides a simple method of fabricating multiple LED devices simultaneously.
An objective of the present invention is to provide a method with simple steps of fabricating LED devices to increase the production rate.
Another objective of the present invention is to provide a method to selectively fabricate a one color LED device or an LED display module with multiple colors.
Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.